diff --git a/gdb/nat/x86-xstate.c b/gdb/nat/x86-xstate.c
new file mode 100644
index 0000000..9fdc572
--- /dev/null
+++ b/gdb/nat/x86-xstate.c
@@ -0,0 +1,67 @@
+/* x86 XSAVE extended state functions.
+
+   Copyright (C) 2022-2023 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "gdbsupport/common-defs.h"
+#include "gdbsupport/x86-xstate.h"
+#include "nat/x86-cpuid.h"
+#include "nat/x86-xstate.h"
+
+/* Fetch the offset of a specific XSAVE extended region.  */
+
+static int
+xsave_feature_offset (uint64_t xcr0, int feature)
+{
+  uint32_t ebx;
+
+  if ((xcr0 & (1ULL << feature)) == 0)
+    return 0;
+
+  if (!x86_cpuid_count (0xd, feature, nullptr, &ebx, nullptr, nullptr))
+    return 0;
+  return ebx;
+}
+
+/* See x86-xstate.h.  */
+
+int
+x86_xsave_length ()
+{
+  uint32_t ecx;
+
+  if (!x86_cpuid_count (0xd, 0, nullptr, nullptr, &ecx, nullptr))
+    return 0;
+  return ecx;
+}
+
+/* See x86-xstate.h.  */
+
+x86_xsave_layout
+x86_fetch_xsave_layout (uint64_t xcr0, int len)
+{
+  x86_xsave_layout layout;
+  layout.sizeof_xsave = len;
+  layout.avx_offset = xsave_feature_offset (xcr0, X86_XSTATE_AVX_ID);
+  layout.bndregs_offset = xsave_feature_offset (xcr0, X86_XSTATE_BNDREGS_ID);
+  layout.bndcfg_offset = xsave_feature_offset (xcr0, X86_XSTATE_BNDCFG_ID);
+  layout.k_offset = xsave_feature_offset (xcr0, X86_XSTATE_K_ID);
+  layout.zmm_h_offset = xsave_feature_offset (xcr0, X86_XSTATE_ZMM_H_ID);
+  layout.zmm_offset = xsave_feature_offset (xcr0, X86_XSTATE_ZMM_ID);
+  layout.pkru_offset = xsave_feature_offset (xcr0, X86_XSTATE_PKRU_ID);
+  return layout;
+}
diff --git a/gdb/nat/x86-xstate.h b/gdb/nat/x86-xstate.h
new file mode 100644
index 0000000..30f3a35
--- /dev/null
+++ b/gdb/nat/x86-xstate.h
@@ -0,0 +1,35 @@
+/* x86 XSAVE extended state functions.
+
+   Copyright (C) 2022-2023 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef NAT_X86_XSTATE_H
+#define NAT_X86_XSTATE_H
+
+#include "gdbsupport/x86-xstate.h"
+
+/* Return the size of the XSAVE extended state fetched via CPUID.  */
+
+int x86_xsave_length ();
+
+/* Return the layout (size and offsets) of the XSAVE extended regions
+   for the running host.  Offsets of each of the enabled regions in
+   XCR0 are fetched via CPUID.  */
+
+x86_xsave_layout x86_fetch_xsave_layout (uint64_t xcr0, int len);
+
+#endif /* NAT_X86_XSTATE_H */